Tensile and impact properties of microwave sintered tungsten heavy alloys

The present study investigates the interrelationship between microstructure, tensile and impact properties of microwave sintered tungsten heavy alloys. Alloys of two different compositions were microwave sintered and conventionally liquid phase sintered using similar heating rate, followed by microstructure and mechanical property evaluation. The tensile properties of microwave sintered alloys were significantly superior to those of liquid phase sintered alloys in both the compositions. Excellent impact properties were obtained in microwave sintered alloys, without any subsequent heat treatment or processing. In order to understand the reasons for the improvement, a detailed comparative study of microstructural features in both microwave and conventionally sintered alloys was carried out and it was observed that both tensile and impact properties of these alloys were largely influenced by tungsten–tungsten contiguity; the weakest link in the microstructure. Microwave sintered alloys were found to exhibit substantially lower contiguity as compared to the conventionally sintered alloys and consequently their properties were found to be superior as compared to the conventionally sintered alloys.